Centrifuge bucket



NOV. 6, 1934. s, R BERGMAN 3,979,953

CENTRIFUGE BUCKET Filed July 13, 1932 Fig. 2.

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Patented Nov. 6, 193@ UNITED STATES CENTBIFUGE BUCKET Sven R. Bergman,Nahant, Mass., assignor to General Electric Company, a corporation ofNew York Application July 13, 1932, Serial No. 622,272

Claims.

The present invention relates to centrifuge buckets such as are used inthe spinning of rayon. One object of my invention is to provide animproved construction and arrangement of bucket wherein the bucket isreinforced with metal in a manner such that it is capable of operatingciciently at high speeds and at the same time is not affected adverselyby the acid solution to which it is subjected.

A further object of my invention is to provide an improved method ofmanufacturing such a bucket.

For a consideration of what I believe to be novel and my invention,attention is directed to the 5 following specification and the claimsappended thereto.

In the drawing, Fig. 1 is a side elevation of a preform used inconstructing a bucket embodying my invention; Fig. 2 is a side elevationillustrating further steps which are utilized in carrying out myinvention; Fig. 3 is a vertical sectional view showing additional stepsused in carrying out my invention; Fig. 4 is a sectional view of acompleted bucket, and Fig. 5 is a detailed view.

Referring to the drawing, Fig. 4, which shows a completed bucketembodying my invention, 1 indicates the side wall provided withcircumferentially extending rings of spaced holes 2 for the escape ofacid, 3 indicates the bottom wall, and 4 indicates the hub provided withopening 5 to receive the driving spindle. The rows of holes 2 are spacedapart a suitable distance and between such rows, side wall 1 is providedwith shallow circumferentially extending grooves 6 in which is woundreinforcing wire 7. Grooves 6 are preferably connected to each other byangularly extending slots 8 as shown in Fig. 2 so that the lreinforcingwire 7 may be one continuous wire extending from top to bottom of sidewall l.

'I'he bucket is constructed from an acid resisting moldable material. Asa moldable material, -I utilize preferably spinnable textile fibres, for

example woven or unwoven cotton impregnated with and held in a highlycompressed state by an artificial resin such as a phenolic condensationproduct. The side walls may be constructed from woven cotton duck unitedby artificial resin while 0 the bottom wall and hub, in which thestresses are not so high, maybe constructed from unwoven cotton unitedby an artificial resin or from small pieces of woven cotton cloth (forexample, pieces of sc'rap material) united by an articial resin. Anartificial resin, such as a. phenolic con- Vof the turns of wireindependent of the anchordensation product, is acid resisting and formsa covering which protects the cotton bres from the acid.

To protect the wire from the acid and to form a bond between yit and theside wallA 1, I utilize Wire provided with a Wrapping 7 of acidresisting material which forms a bond with side wall 1. For thispurpose, -I use preferably cotton covered wire wherein the cottoncovering is impregnated with artificial resin. I have found steel wirehaving a quadruple cotton covering to be satisfactory. During themolding operation, the articial resin integrally unites the coverings onsuccessive turns of wire with each other and with side wally 1, thusforming a unitary structure. This is a feature of my invention which Iregard as being important since by this arrangement, ify one or moreturns of wire become broken, it does not affect appreciably the strengthof the wire reinforcement for by the arrangement described, each turnbecomes in substance independent of the other turns in so far as itsfunction of reinforcing is concerned. 'Ihe arrangement has the advantagealso that it makes the holding in place ing of the ends of the wire.

In constructing a bucket according to my invention, I first take themoldable material from which the bucket is to be constructed and make apreform as shown in Fig. 1, which has the general contour of thecompleted bucket. The side walls 1 may be constructed from -successivelayers of woven cotton duck and may be formed by winding a strip ofcotton duck of suitable width on a mandrel, the duck having lbeentreated before winding with the artificial resin. The preformis-constructed by placing the moldable material in a suitable mold andgiving it an initial pressing at a suitable temperature to cause it totake the desired shape and adhere together, the operation being such asnot to completely cure the moldable material. The preform is then takenfrom the mold and the grooves 6 and slots 8 are cut therein, there beingleft between the grooves the lands 9 in which the openings 2 are to beformed. At this time, I form also grooves 10 and 11 which receive theends of the reinforcing wire. I next take wire which is to form thereinforce- -ment, it being in the illustrated embodiment of my inventiona wire having a cotton covering which has been treated with articialresin and dried, place one end in the groove 10, and wrap the wire undersuitable tension in the grooves 6, the successive turns of the wirebeing in close engagement with each other and the wire passing type iswell known in the art and requires no detailed description. When nished,the bucket is smooth on the outside and the steel wire is completelyprotected by the acid resisting cover- 111g.

A It is important that a bucket of this type be as smooth on the outsideas possible and to improve the bucket in this respect, I may provide onthe outside of the bucket a special wrapping of thin Woven cloth such asthin tape. For example, I have found cotton tape of a thickness of theorder of 0.007 of an inch satisfactory. The tape is first treated withthe adhesive, such as an artificial resin, after which it is wound onthe outside of the bucket, successive turns overlapping, it beingapplied after the Wire is Wound on and before the final moldingoperation. The tape in process of being Wound, is indicated at 12 inFig. 3, it being wound so that successive layers overlap about one-halftheir width. The bucket is then given the final molding operation andwhen completed, the tape provides a thin integral covering which is verysmooth on the outer surface. In the nished bucket, Fig. 4, the tapecovering is indicated at 13.

In connection with my improved construction, it is to be noted that thereinforcing wire is not embedded in the body of the bucket but is woundon the outer surface thereof. This is an important consideration becauseby locating the wire on the surface, the maximum reinforcing effect isobtained. The winding of the wire on the outer surface is made possibleby reason of the fact that the wire is covered with the acid resistingcoating and, as pointed out above, the fact that this acid resistingcoating adheres to the material of the side Wall adds greatly to thereliability of the structure since if one or more turns of wire becomebroken, the other turns are not affected and the strength of thestructure appreciably decreased.

is not- The method disclosed in this application is not claimed hereinas it forms the subject matter of my divisional application Serial No.694,979, led October 24, 1933.

What I claim as new and desire to secure by Letters Patent of the'UnitedStates, is:-

1. A centrifuge bucket comprising non-metallic sidewalls of acidresisting material, and a metallic reinforcing member wound on the outersurface of said side Walls, the turns of said member being covered withacid resisting material which is integrally united to the material ofthe side walls.

2, A centrifuge bucket comprising non-metallic side walls of acidresisting material, and a continuous metallic reinforcing member wound.on the outer surface of said side walls, the turns of said member beingcovered with acid resisting material which is integrally united to thematerial of the side walls, and turns being spaced apart at intervals toprovide spaces having openings therein for the escape of acid.

3. A centrifuge bucket comprising side walls formed from textile iibresunited by an artificial resin, and reinforcing means` for .the sideWalls comprising turns of wire on the outer surface of the side Walls,the turns being covered with textile bres united and joined to the sidewalls by artificial resin.

4. A centrifuge bucket comprising non-metallic side walls of acidresisting material, a metallic reinforcing member wound on the outersurface of said side Walls, the turns of said member being covered withacid resisting material which is integrally united to the material ofthe side Walls, and a thin covering of Woven fabric on the outer surfaceof the bucket to give it a smoothv 5. A centrifuge bucket comprisingside walls formed from textile fibres united by an articial resin,reinforcing means for the side walls comprising turns of wire on theouter surface of the side walls, the turns being covered with textilefibres united and joined to the side Walls by articial resin, and a thincovering of Woven textile material on the outer surface of the bucketunited therewith by articial resin.

SVEN R. BERGMAN.

